Public Relations are a notoriously difficult function to measure. More often than not, we use an advertising value equivalent, which, most obviously, gives you just that – the equivalent of a paid advertisement. Though widely criticised, not one accepted alternative to this has materialised.
Someone once said “Advertising you pay for, PR you pray for”, which I feel perfectly sums up the idea. It is proven that readers acknowledge and remember editorial over advertisements. The fact is consumers don’t feel as though they are being bought when they watch or read about something. Now, let’s not say readers have complete trust in journalists, but it would give the cause a bit more credibility if an established publication outlined the key factors that actually make a product work.